https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93689
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Actually the issue might be just one, even the gimplifier ICE seems to be caused by a CAST_EXPR leaking where it should not. Maybe we fail to substitute default arguments in lambdas in a template parameter list.
